Macrophage diversity and polarization: in vivo veritas on the development of methods that distinguish human CECs derived from tumor and bone marrow. Elucidation of the origin of the patients’ apoptotic CECs will clarify the role of host-versus-tumor differences in CEC responses, which will have implications for the broader significance of this study to other types of cancers and treatments. More extensive translational clinical trials that follow a larger number of patients for a longer-term follow-up will determine whether a simple blood test can be used to identify and monitor cancer patients who will benefit from novel antiangiogenic therapies.■